Rocker chiller

ABSTRACT

In one embodiment, a method of reducing the temperature and increasing the moisture content of carcasses includes progressively introducing the carcasses into a body of heat-exchanging fluid in a tank having a curved bottom surface, oscillating a paddle in the tank along the curved bottom surface to upwardly and laterally urge the carcasses through the body of fluid, and axially propelling jets of heat-exchanging fluid through the body of fluid to axially urge the carcasses along the length of the tank toward an outlet end of the tank.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to co-pending U.S. provisional application entitled “Rocker Chiller” having U.S. Ser. No. 60/760,616 and filed Jan. 20, 2006, and which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure generally relates to a rocker chiller that reduces the temperature and increases the moisture content of poultry carcasses, and more specifically to a propulsion system that axially urges the carcasses through the rocker chiller.

BACKGROUND

Paddle type chillers have a long history of use in poultry and other food processing industries. The basic principle of operation is that a paddle or broad blade is used to agitate poultry carcasses in a tank of cold water to chill the carcasses. Continuous replacement of water in one end of the tank by colder water and removal of warmer water at the other end of the tank provides the mechanism for removing heat from the product and for moving the carcasses along the length of the tank. The motion of a paddle assures thorough contact between the water and the product. The motion of the paddle is typically either continuous rotation about a horizontal axis or a rocking motion about a horizontal axis through a range of approximately 60 to 120 degrees.

Operational drawbacks of paddle chillers have been noted, and paddle chillers have had limited penetration of the commercial market. Among these drawbacks is the lack of consistency in the temperature and moisture content of product removed from the chiller, and the related problem of variation in the rate of product throughput particularly at the end of operations when the chiller is being emptied. The current invention addresses these and other operational problems.

SUMMARY

In one embodiment, the invention includes a method of reducing the temperature and increasing the moisture content of carcasses by progressively introducing the carcasses into a body of heat-exchanging fluid in a tank having a curved bottom surface. Oscillating a paddle in the tank along the curved bottom surface urges the carcasses along the curved bottom surface through the body of fluid, and applying axially propelling jets of heat-exchanging fluid through the body of fluid urges the carcasses axially along the length of the tank toward an outlet end of the tank.

In another embodiment, a system for reducing the temperature of carcasses includes an elongated tank configured to hold a body of heat-exchanging fluid, and a paddle assembly that urges the carcasses upwardly and laterally through the body of heat-exchanging fluid. The paddle assembly includes an elongated paddle blade positioned in the tank and a crank mechanism that oscillates the paddle blade. A propulsion system axially and laterally urges the carcasses along the length of the tank. The propulsion system includes nozzles that direct jets of heat-exchanging fluid along the length of the tank at the upward positions of the paddle.

In another embodiment, a chiller includes an elongated tank having a curved bottom portion, means for circulating heat-exchanging fluid within the tank, an elongated paddle positioned in the tank and extending along a length of the tank, means for oscillating the paddle in the tank along a path generally conforming to the curved bottom portion of the tank, and fluid outlet ports oriented to direct heat-exchanging fluid along the length of the tank to urge carcasses along the length of the tank.

Other systems, devices, methods, features, and advantages of the disclosed rocker chiller will be apparent or will become apparent to one with skill in the art upon examination of the following figures and detailed description. All such additional systems, devices, methods, features, and advantages are intended to be included within the description and are intended to be protected by the accompanying claims.

BRIEF DESCRIPTION OF THE FIGURES

The present disclosure may be better understood with reference to the following figures. Matching reference numerals designate corresponding parts throughout the figures, and components in the figures are not necessarily to scale.

FIG. 1 is a perspective view of an exemplary embodiment of a rocker chiller.

FIG. 2 is an end view of the rocker chiller shown in FIG. 1.

FIG. 3 is a partial perspective view of the embodiment of the rocker chiller shown in FIG. 1, illustrating an inlet end of a tank with a crank mechanism removed.

FIG. 4 is a block diagram of a method of reducing the temperature and increasing the moisture content of poultry carcasses.

DETAILED DESCRIPTION

Referring now in more detail to the drawings, in which like numerals indicate like parts throughout the several views, FIG. 1 is a perspective view of a rocker chiller 100 configured to reduce the temperature and increase the moisture content of edible articles, such as eviscerated poultry carcasses (not shown). The rocker chiller 100 generally includes a tank 102, a paddle assembly 104, a propulsion system 106, and a re-chilling system 108. The tank 102 is configured to hold a body of heat-exchanging fluid 110, such as water that usually includes other chemicals compatible for reducing bacterial content of the water. Carcasses introduced into an inlet end 112 of the tank 102 are cooled by and absorb some of the heat-exchanging fluid 110 before being removed from the outlet end 114 of the tank 102. The re-chilling system 108 removes the heat-exchanging fluid 110 from the outlet end 114 of the tank 102, lowers its temperature, and reintroduces the heat-exchanging fluid 110 into the tank 102 from above. The continual removal of carcasses and heat-exchanging fluid 110 at the outlet end 114 of the tank and the continued addition of carcasses at the inlet end 112 of the tank creates a general flow from the inlet end 112 of the tank 102 to the outlet end 114. As the carcasses migrate toward the outlet end 114, the paddle assembly 104 oscillates a paddle blade through the tank 102, stirring the carcasses to decrease the temperature of the carcasses and to increase their moisture content. The propulsion system 106 urges the carcasses axially along the length of the tank 102 toward the outlet end 114 while further reducing the temperature and increasing the moisture content of the carcasses, as described below. More specifically, the propulsion system 106 includes at least one nozzle or spout that introduces a stream of relatively high velocity heat-exchanging fluid 110 into the tank 102 at the inlet end 112.

The tank 102 is generally formed from an elongated longitudinal wall 116. The longitudinal wall 116 has a curved bottom portion 118. In the illustrated embodiment, the longitudinal wall 116 is approximately semi-cylindrical. In other embodiments, the longitudinal wall 116 may be substantially U-shaped, including the curved bottom portion 118 and upwardly extending parallel portions that increase the height of the tank 102 along the sides. Enclosing the longitudinal wall 116 at its edges are an end wall 120 at the inlet end 112 of the tank 102, and an end wall 122 at the outlet end 114 of the tank 102. A longitudinal axis 124 extends between the end walls 120 and 122 from the inlet end 112 to the outlet end 114 of the tank 102. In the illustrated embodiment, the end walls 120 and 122 are substantially parallel to each other, although other configurations are possible.

The tank 102 can have a variety of shapes, sizes, and volumes, and can be formed from a variety of materials. For example, the tank 102 may have a length between about 20 feet and about 35 feet. A width of the tank 102 may be between about 8 feet and 12 feet, and a height of the tank 102 may be between about 8 and 10 feet. In such embodiments, a capacity of the tank 102 is between about 250 and 450 gallons per linear foot. An example of a material that can be used to form the walls 116, 120 and 122 of the tank 102 is stainless steel. However, other materials and shapes can be used.

In some embodiments, the tank 102 is configured so that the force of gravity influences the movement of the carcasses from the inlet end 112 to the outlet end 114. For example, the longitudinal wall 116 of the tank 102 may tilt slightly toward the outlet end 114. Alternatively, a plurality of adjustable leveling feet 125 that support the tank 102 can be adjusted so that the outlet end 114 is slightly lower than the inlet end 112.

The tank 102 is filled with the heat-exchanging fluid 110, which at least initially has a relatively lower temperature than the carcasses. The carcasses are introduced into the tank 102 at the inlet end 112, such as by dropping the carcasses from a conveyor into the tank 102 from above. The heat-exchanging fluid 110 accepts heat from the carcasses, so that the temperature of the carcasses decreases and the temperature of the heat-exchanging fluid 110 increases. The re-chilling system 108 continually re-circulates and re-chills the heat-exchanging fluid 110 from the outlet end 112 to the inlet end 114, so that the warm fluid is chilled and can again accept heat from the carcasses. More specifically, the re-chilling system 108 removes the heat-exchanging fluid 110 from the outlet end 114 of the tank 102, lowers the temperature of the fluid, and re-circulates the fluid back into the tank 102 at a colder temperature. Therefore, the re-chilling system 108 is a means for circulating heat-exchanging fluid 110 within the tank 102.

In the illustrated embodiment, the re-chilling system 108 includes an outlet conduit 126, a heat exchanger 128, a pump 130, and inlet conduit 132. The heat-exchanging fluid 110 exits the outlet end 114 of the tank 102 through an outlet opening at or in the end wall 122, and travels through the outlet conduit or pipe 126 to the heat exchanger 128. The heat exchanger 128 removes heat from the heat-exchanging fluid 110, and the pump 130 pumps the heat-exchanging fluid back into the tank 102 through the inlet conduit 132. In the illustrated embodiment, the inlet conduit 132 extends along a portion of the length of the tank 102 adjacent an upper edge of the tank, and a plurality of nozzles extends from the inlet conduit 132 over the tank 102. The heat-exchanging fluid 110 descends into the tank 102 from above through the nozzles, although other configurations are possible. Because of evaporation and the carcasses accepting moisture from the heat-exchanging fluid 110, the re-chilling system 108 may also introduce make-up heat-exchanging fluid 110 into the re-chilling system 108 to account for the fluid lost during the chilling process, so that a relatively consistent fluid level 133 is maintained in the tank 102 (FIG. 2).

The continual addition of carcasses into the inlet end 112 of the tank 102, along with the continual removal of heat-exchanging fluid 110 and carcasses from the outlet end 114 of the tank, creates a general flow or current from the inlet end 112 to the outlet end 114. The carcasses can slowly migrate on this current toward the outlet end 114, where an outlet assembly 134 removes the carcasses from the tank 102 and delivers the carcasses to, for example, a conveyor. While a variety of outlet assemblies could be employed, in the illustrated embodiment the outlet assembly 134 is a conventional rotating windmill-type assembly having a hub that is coupled to the end wall 122 at the outlet end 114. A drive (not shown) rotates the windmill about the hub in a direction that is generally perpendicular to the longitudinal axis 124 of the tank 102. As the windmill rotates, the carcasses become positioned on plates located on spokes that extend radially outward from the hub. The plates slope slightly toward the end wall 122 so that once a carcass is positioned on a plate, continued rotation of the windmill elevates the carcass from the heat-exchanging fluid 110. A chute (not shown) that extends away from the end wall 122 delivers the carcasses from the windmill to a conveyor located outside the rocker chiller 100 (not shown).

To promote the removal of heat and the addition of moisture to the carcasses, the rocker chiller 100 includes the paddle assembly 104. The paddle assembly 104 is mounted about an axle 138 aligned with the longitudinal axis 124 of the tank 102 and extending between the end walls 120 and 122. Paddle support arms 136 extend radially from the axle 138 at intermittent positions along the length of the axle 138. The paddle support arms 136 support at their distal ends an elongated paddle blade 140. As shown in FIG. 2, which is an end view of the rocker chiller 100 shown in FIG. 1, the paddle support arms 136 are sized to extend from the axle 138 to the concave inner surface of the longitudinal wall 116 of the tank 102, so that the paddle blade 140 is positioned closely adjacent the concave longitudinal wall 116. The paddle blade 140 increases in width with increased distance from the axle 138, so that the paddle blade 140 forms an obtuse angle with the longitudinal wall 116.

As shown in FIG. 1, the paddle assembly 104 is coupled to a power means for oscillating the paddle assembly 104 in the tank 102. The power means may be an electric motor, hydraulic motor or other device that imparts the motion to the paddle assembly. In the illustrated embodiment, the power means for oscillating the paddle assembly 104 is a crank mechanism 142 mounted to the end wall 120 and driven by a motor 144 and reduction gears 146, as shown in FIG. 1, although other configurations are possible.

As shown in FIG. 2, the paddle assembly 104 oscillates along a path that follows the curved bottom portion 118 of the tank 102. In embodiments in which the curved bottom portion 118 is substantially semi-cylindrical, the paddle assembly oscillates through an arc 148 of, for example, about 60° to about 120° between up positions 150 and 152 of the arc 148. From a vertical position, an upward reach of the paddle assembly 104 to the up position 150 of the arc 148 is about 30° to about 60° from the vertical position in the clockwise direction. The upward reach of the paddle assembly 104 to the up position 152 of the arc 148 is about 30° to about 60° from the vertical position in the counterclockwise direction. Preferably, the amplitude of the arc 148 is such that the paddle assembly 104 remains below the fluid level 133 throughout the oscillation, avoiding the likelihood of the paddle assembly 104 elevating the carcasses out of the heat-exchanging fluid 110 as it rocks back and forth along the arc 148. In motion, the paddle assembly 104 sweeps toward the up position 150 of the arc 148, reverses course, and sweeps in the reverse direction to the up position 152 of the arc 148, and again reverses course. Therefore, the up positions 150 and 152 are on opposite sides of the tank.

The oscillation of the paddle assembly 104 urges the carcasses upwardly and laterally, facilitating heat transfer from the carcasses to the heat-exchanging fluid 110, and facilitating moisture transfer from the heat-exchanging fluid 110 to the carcasses. For example, because most of the carcasses usually are relatively heavier than the heat-exchanging fluid 110 in which they are submerged, the carcasses are disposed to slowly sinking in the tank 102. The rocking of the paddle assembly 104 stirs the carcasses, levitating the carcasses up into the heat-exchanging fluid 110 from the bottom to assure thorough contact with the heat-exchanging fluid 110. The momentum imparted on the carcasses allows them to remain temporarily suspended in the relatively colder heat-exchanging fluid 110 before again sinking toward the bottom. The oscillation of the paddle assembly 104 tends to break up clusters of carcasses to create a relatively uniform distribution of carcasses within the tank 102, and promotes heat transfer by continually replacing the heat-exchanging fluid 110 adjacent the carcass body.

The movement of the paddle assembly 104 may be relatively slow. For example, the paddle assembly 104 may take about 3 seconds to about 30 seconds to perform a single oscillation. The slow movement of the paddle assembly 104 gently massages the carcasses and moves the carcasses so that the carcasses gently bump against and separate from one another. The carcasses also gently bump against the paddle blade 140 and the longitudinal wall 116. This gentle engagement allows the carcasses to absorb and retain the heat-exchanging fluid 110 within the muscle of the carcass, without bruising the carcass muscle or damaging the carcass bone. Bruising and damaging is also reduced by the shape of the paddle blade 140, which forms the obtuse angle with the surface of the longitudinal wall 116, so that carcasses passing adjacent the paddle blade 140 are gently tumbled away from the longitudinal wall 116 instead of getting caught or pushed into the longitudinal wall 116.

At the up positions 150, 152 of each sweep through the arc 148, the motion of the paddle assembly 104 instantaneously pauses as the direction of travel is reversed. This instantaneous pause can be extended in duration to create intermittent periods of rest, in which the carcasses are allowed to descend and idle, between the periods of oscillation, in which the carcasses gently interact with the paddle blade 140 and with other carcasses. The periods of rest may be as short as a second to as long as several minutes. The alternating periods of massage and rest facilitate moisture retention by the carcasses within the muscles. As explained above, some of the heat-exchanging fluid 110 is absorbed into the carcass muscle as the carcasses migrate from the inlet end 112 to the outlet end 114. Therefore, in addition to having a relatively lower temperature, the carcasses are also relatively heavier at the outlet end 114 due to the increased moisture content.

Although the paddle assembly 104 is described above as having a specific configuration, a person of skill would appreciate that the paddle assembly 104 can have other configurations in other embodiments. For example, several paddle support arms 136 and paddles could be used. Additionally, the rocker chiller 100 could include multiple different paddle assemblies 104 supported on different axles 138 and driven by different crank mechanisms 142. The crank mechanism 142 could be otherwise positioned, including positions in which the crank mechanism 142 is mounted overhead, and the crank mechanism 142 could oscillate the paddle assembly 104 through an arc 148 having larger or smaller ranges of amplitudes. In some embodiments, the paddle assembly 104 may continuously rotate about the axle 138 instead of oscillating. In such embodiments, the paddle assembly 104 may have multiple sets of paddle support arms 136 extending radially outward from the axle 138 in multiple directions, each set of paddle support arms supporting a different paddle blade 140. For example, the paddle assembly 104 may be X-shaped when viewed from the end walls 120, 122. Because the paddle assembly 104 has multiple paddle blades 140 in such embodiments, the carcasses are continually stirred even when the paddle blade 140 is elevated above the fluid level 133. In still other embodiments, the paddle blade 140 may not form the obtuse angle with the longitudinal wall 116, or the paddle support arms 136 may be sized so that the paddle blade 140 is spaced apart from the longitudinal wall 116. In such embodiments, the carcasses pass between the paddle blade 140 and the longitudinal wall 116 with relative ease, without getting trapped or damaged.

Because the paddle assembly 104 pivots about the longitudinally extending axle 138, the paddle assembly 104 oscillates upwardly and laterally. Therefore, the paddle assembly 104 urges the carcasses both upwardly and laterally, but does not urge the carcasses axially, meaning parallel to longitudinal axis 124 of the tank 102 from the inlet end 112 to the outlet end 114. As mentioned above, the continual addition of heat-exchanging fluid 110 and carcasses to the inlet end 112, along with the continual removal of heat-exchanging fluid 110 and carcasses from the outlet end 114, creates the general current from the inlet end 112 to the outlet end 114 of the tank, and the carcasses can migrate toward the outlet end 114 of the tank 102 on this relatively slow-moving current. However, the current does not positively urge or propel the carcasses axially along the length of the tank 102 at the inlet end of the tank. Further, when the carcasses and heat-exchanging fluid 110 are no longer being introduced into the tank 102, such as at the end of the day, the slow-moving current may dissipate and the carcasses may stagnate at their current position.

Therefore, the rocker chiller 100 includes a propulsion system 106 that axially urges the carcasses along the length of the tank 102. The propulsion system 106 generally comprises a plurality of spouts or nozzles 156, 158 (FIGS. 2 and 3) and a supply system 154 (FIGS. 1 and 3). As shown in FIG. 2, the nozzles 156, 158 are positioned in openings in the end wall 120 at the inlet end 112 of the tank 102. The nozzle 156, 158 are oriented to axially direct heat exchanging fluid 110 though the tank 102. More specifically, the nozzles 156, 158 are positioned to communicate heat-exchanging fluid 110 through the end wall 120 at a relatively high velocity, creating jets 160, 162 of heat-exchanging fluid 110 traveling axially through the body of heat-exchanging fluid 110 within the tank 102, as shown in FIG. 3. These jets 160, 162 of heat-exchanging fluid 110 axially propel the carcasses toward the outlet end 114 of the tank 102. The supply system 154 supplies the heat-exchanging fluid 110 to the nozzles 156, 158 under pressure, as shown in FIG. 1.

The nozzles 156, 158 may have a diameter of about one-half to about two inches and may be configured to expel heat-exchanging fluid 110 at a rate of about 50 to 300 gallons per minute. In such an embodiment, the jets 160, 162 may dissipate about 10 to 35 feet along the length of the tank 102. In FIG. 2, three nozzles are shown. The two upper nozzles 156 are positioned in the end wall 120 adjacent and just above the upper reach of the paddle assembly 104, such that the upper jets 160 are high enough in the tank 102 to be out of the sweep of the paddle assembly 104. When the paddle assembly 104 reaches the up positions 150, 152 of the arc 148, the upper jets 160 are just above the position of the paddle blade 140. Due to this positioning, the paddle assembly 104 intermittently urges the carcasses into the upper jets 160, and the upper jets 160 axially urge the carcasses along the length of the tank 102 toward the outlet end 114. This maintains the sequence of carcasses, so that the carcasses are removed from the tank 102 in relatively the same order that they entered the tank. Such sequencing ensures the residence time of the carcasses in the tank 102 is relatively consistent and uniform. In some embodiments, the upper nozzles 156 are used during normal operation, but are not used when the tank 102 is being emptied.

The third lower nozzle 158 is positioned in the end wall 120 at the bottom center of the rocker chiller 100. The lower nozzle 158 may only be used when the tank 102 is being emptied, such as at the end of the day. When the fluid level 133 in the tank is lowered, the lower nozzle 158 provides a lower jet 162 of heat-exchanging fluid 110 that propels the carcasses toward the outlet end 114 of the tank 102, so that the carcasses can be removed. The use of the lower nozzle 158 may be particularly useful in cases in which the slow-moving current has dissipated, and the paddle assembly 104 has stopped oscillating. In such cases, the carcasses that languish at the bottom of the tank 102 are urged toward the outlet end 114 by the lower nozzle 158.

As shown in FIG. 1, the supply system 154 includes an outlet conduit 164 that communicates the heat-exchanging fluid 110 from the interior of the tank 102 to a sump 166, and a delivery conduit 168 that delivers the heat-exchanging fluid 110 from the sump 166 to the nozzles 156, 158 at the end wall 120. So that the heat-exchanging fluid 110 passing through the nozzles 156, 158 is at a relatively high pressure, a rotary pump 170 driven by a motor 172 is positioned along the delivery conduit 168. For example, the rotary pump 170 may be configured to operate at about 15 to 80 pounds per square inch, although other configurations are possible. The motor 172 may be about a 10 to 40 horsepower motor, although other configurations are possible. The rotary pump 170 and motor 172 pressures the heat-exchanging fluid 110, so that the fluid at the end wall 120 travels at a relatively high velocity through the tank, forming the jet. As shown in FIG. 3, the delivery conduit 168 branches at the end wall 120 and connects to each of the nozzles 156, 158.

In other embodiments, the propulsion system 106 can have other configurations. For example, greater or fewer upper nozzles 156 and/or lower nozzles 158 can be used, and the nozzles can be positioned in the end wall 120 other than as shown in FIG. 2. Nozzles can also be positioned along the length of the tank 102, so that the jets are created along the length of the tank and not just at the inlet end 112. The outlet conduit 164 can be positioned at any point along the tank 102 or may be omitted completely, in which case an external system supplies heat-exchanging fluid 110 into the delivery conduit 168. The supply system 154 can also include a heat exchanger that reduces the temperature of the heat-exchanging fluid 110. In this and in other embodiments, the supply system 154 may share one or more of its components with the re-chilling system 108, which generally re-circulates and re-chills the heat-exchanging fluid 110 as described above.

The jets 160, 162 also facilitate improved heat transfer from the carcasses, and moisture retention by the carcasses. Typically, the carcasses are eviscerated shortly before being introduced into the inlet end 112 of the tank 102, and temporarily retain their natural body heat. In many cases the carcasses are also de-feathered, and temporarily retain the heat introduced into the carcasses during the de-feathering process. Therefore, the carcasses are relatively warm when introduced into the tank 102. For example, the carcasses may have a temperature of about 105 degrees.

Because the carcasses are relatively warm when introduced into the inlet end 112, the heat-exchanging fluid 110 adjacent the surface of the carcass becomes warm relatively quickly. The jets 160, 162 propel high velocity heat-exchanging fluid 110 past the surface of the carcasses at the inlet end 112 where the carcasses are the relative warmest, continuously replacing the heat-exchanging fluid 110 that contacts and accepts heat from the carcass to facilitate heat transfer. Particularly, the upper nozzles 156 enable vigorous heat exchange at the upper reach of the paddle assembly 104. Additionally, the carcasses are predisposed to accepting and retaining moisture when warm, and therefore the upper jets 160 propel the high velocity heat-exchanging fluid 110 through and along the carcasses at the location in the tank 102 where the ability of the carcasses to absorb the heat-exchanging fluid into the carcass muscle is heightened.

In some embodiments, air nozzles 174 enhance the heat transfer between the carcasses and the heat-exchanging fluid 110, as shown in FIG. 2. The air nozzles 174 communicate air into the interior of the tank 102, which introduces rapidly rising air bubbles into the heat-exchanging fluid 110. The air bubbles tend to disturb the carcasses and to create turbulence in the heat-exchanging fluid 110 surrounding the carcasses, enhancing heat transfer between the carcasses and the heat-exchanging fluid 110. The air nozzles 174 are positioned through the longitudinal wall 116 of the tank 102 at intervals along the length of the tank 102. Each interval includes several air nozzles 174 that are spaced apart around the curved bottom portion 118. An air compressor (not shown) provides air under pressure to an air conduit (not shown), which communicates the air to the interior of the tank through the air nozzles 174. In some embodiments, each air nozzle 174 has a control valve (not shown) positioned between the air nozzle 174 and the air conduit (not shown), which can be used to control the air nozzle 174. In other embodiments, the air nozzles 174 are omitted.

FIG. 3 is a block diagram illustrating a method 300 of reducing the temperature and increasing the moisture content of poultry carcasses. In block 302, the carcasses are progressively introduced into a body of heat-exchanging fluid in a tank having a curved bottom surface. The progressive introduction of the carcasses into an inlet end of the tank, along with the progressive removal of the carcasses from an outlet end of the tank, creates a slow-moving current traveling axially along the tank from the inlet end to the outlet end. The carcasses slowly migrate toward the outlet end along this current.

In block 304, a paddle assembly is oscillated in the tank along the curved bottom surface to upwardly and laterally urge the carcasses through the heat-exchanging fluid. The oscillation of the paddle assembly facilitates heat transfer from and moisture retention by the carcasses. The paddle assembly oscillates through an arc that substantially follows the curved bottom surface of the tank.

In some embodiments, the paddle assembly intermittently stops so that periods of rest, in which the carcasses absorb and retain moisture from the heat-exchanging fluid 110, are inter-spaced throughout periods of oscillation, in which the carcasses are massaged by the paddle assembly and by gentle interaction with other carcasses. For example, when the paddle assembly reaches upper points of the arc through which it oscillates the paddle assembly instantaneously pauses to change direction. The instantaneous pause can be extended in duration to form the period of rest. The periods of rest may be as short as a second to as long as several minutes.

In some embodiments, the paddle assembly oscillates during a normal operation period. When the carcasses are no longer being introduced into the tank, such as during an end of operation period when the tank is being emptied, the paddle assembly may cease oscillating, or may continue oscillating for a brief period before ceasing oscillating.

In block 306, jets of heat-exchanging fluid axially propel the carcasses along the length of the tank toward the outlet end. The jets facilitate sequencing of the carcasses in the tank, and also facilitate heat transfer and moisture retention. In some embodiments, one or more upper jets are created just above the upper points of the arc through which the paddle assembly oscillates, and one or more lower jets are created along the bottom of the tank. The upper jets axially propel the carcasses along the length of the tank during the normal operation period, while the lower jet axially propels the carcasses along the length of the tank during the end of operation period, although other configurations are possible.

It should be noted that the above defined steps 302 to 306 can be performed in any order. For example, in one embodiment, the paddle assembly begins oscillating in block 304. During the normal operation period, the carcasses are progressively introduced into the tank in block 302. The upper jets axially propel heat-exchanging fluid along the length of the tank in block 306. As the carcasses are introduced, the oscillation of the paddle assembly upwardly and laterally urges the carcasses into the upper jets, which axially urge the carcasses along the length of the tank toward the outlet end. Therefore, the sequence of carcasses within the tank is substantially the same as the sequence the carcasses were introduced into the tank.

During the end of operation period, the progressive introduction of carcasses into the tank ceases. The paddle assembly discontinues oscillating, or continues oscillating for a temporary period before ceasing. The upper jets discontinue axially propelling heat-exchanging fluid along the length of the tank. The heat-exchanging fluid is slowly removed from the tank to empty it. The lower jet begins axially propelling heat-exchanging fluid along the bottom of the tank to axially urge the carcasses toward the outlet end during tank emptying. This is but one of many examples of how the steps 302 to 306 of the method 300 could be implemented.

It should be noted that the disclosed rocker chiller 100 can be used in a variety of manners other than the exemplary manner described above. For example, the rocker chiller 100 can be used to raise the temperature of the carcasses such that the carcasses are heated or thawed. In such an embodiment, the heat-exchanging fluid 110 at least initially has a relatively higher temperature than the carcasses, and the re-circulating system adds heat to, instead of removing heat from, the heat-exchanging fluid. Further, the rocker chiller 100 can be employed to exchange heat with objects other than carcasses, including non-edible objects. In other words, the rocker chiller 100 can be described as a heat exchanger that can be employed to accept heat from or deliver heat to an object, including a carcass.

While particular embodiments of a rocker chiller have been disclosed in detail in the foregoing description and figures for purposes of example, those skilled in the art will understand that variations and modifications may be made without departing from the scope of the disclosure. All such variations and modifications are intended to be included within the scope of the present disclosure, as protected by the following claims. 

1. A system for reducing the temperature of carcasses, comprising: an elongated tank configured to hold a body of heat-exchanging fluid; a paddle assembly that moves laterally and urges the carcasses upwardly through the body of heat-exchanging fluid, the paddle assembly including an elongated paddle blade positioned in the tank; a crank mechanism that oscillates the paddle blade to predetermined up positions on opposite sides of the tank; and a propulsion system that axially urges the carcasses along the length of the tank, the propulsion system including at least one nozzle that directs a jet of heat-exchanging fluid along the length of the tank at a position adjacent the paddle assembly when the paddle assembly is at its predetermined up position.
 2. The system of claim 1, wherein the elongated tank has a longitudinal axis and a curved bottom portion, and the crank mechanism oscillates the paddle blade about the longitudinal axis, such that the paddle blade travels upwardly and laterally along an arc that substantially follows the curved bottom portion of the tank.
 3. The system of claim 2, wherein the paddle assembly is configured to intermittently pause the paddle blade for periods of rest.
 4. The system of claim 1, wherein the system further includes a re-chilling system that removes the heat-exchanging fluid from the tank, lowers the temperature of the fluid, and re-circulates the heat-exchanging fluid back into the tank.
 5. The system of claim 1, wherein the nozzles are positioned in an end wall and are directed along the length of the tank at an inlet end of the tank, such that the carcasses introduced into the tank at the inlet end are axially urged toward an outlet end of the tank by the jets.
 6. The system of claim 5, wherein the nozzles include two upper nozzles, each of the upper nozzles being positioned adjacent and above an up position of an arc through which the paddle blade oscillates, such that paddle blade upwardly and laterally urges the carcasses into the jets emerging from the nozzles.
 7. The system of claim 5, wherein the nozzles include at least one lower nozzle positioned at the bottom center of the tank, such that when a fluid level of heat-exchanging fluid in the tank is lowered, the lower nozzle axially propels the carcasses along the bottom of the tank toward the outlet end.
 8. The system of claim 1, wherein the propulsion system further includes a pump that pressurizes the heat-exchanging fluid, and a delivery conduit that communicates the pressurized heat-exchanging fluid from the pump to the nozzles.
 9. The system of claim 1, wherein the jets are volumes of relatively high velocity heat-exchanging fluid traveling through the body of heat-exchanging fluid in the tank, to urge the carcasses through the body of heat-exchanging fluid.
 10. A chiller for reducing the temperature of carcasses, comprising: an elongated tank including a curved bottom portion; means for re-circulating heat-exchanging fluid within the tank; an elongated paddle positioned in the tank and extending along a length of the tank; means for oscillating the paddle in the tank along a path generally conforming to the curved bottom portion of the tank; and fluid inlet ports oriented to direct heat-exchanging fluid along the length of the tank at positions adjacent the path of the paddle to urge the carcasses along the length of the tank.
 11. The apparatus of claim 10, wherein the fluid inlet ports are configured to direct streams of heat-exchanging fluid on opposite sides of the tank at positions below a fluid level in the tank and above an upward reach of the paddle.
 12. The apparatus of claim 10, wherein at least one fluid inlets port is configured to direct a stream of heat-exchanging fluid along a bottom of the tank.
 13. The apparatus of claim 10, wherein the fluid inlet ports include upper fluid inlet ports configured to direct streams of heat-exchanging fluid on opposite sides of the tank at positions above an upward reach of the paddle and below a fluid level in the tank, and at least one lower fluid outlet port, each lower fluid outlet port being configured to direct a stream of heat-exchanging fluid along a bottom of the tank.
 14. A method of reducing the temperature and increasing the moisture content of carcasses comprising: progressively introducing the carcasses into a body of heat-exchanging fluid in a tank having a curved bottom surface; oscillating a paddle in the tank along the curved bottom surface to urge the carcasses upwardly on the curved bottom surface; and propelling jets of heat-exchanging fluid through the body of fluid to urge the carcasses axially along the length of the tank toward an outlet end of the tank.
 15. The method of claim 14, wherein the step of oscillating the paddle comprises intermittently oscillating the paddle during periods of oscillation and pausing the paddle during periods of rest.
 16. The method of claim 15, wherein the heat-exchanging fluid consists essentially of water, and the periods of rest facilitate absorption and retention of the water in muscle of the carcass.
 17. The method of claim 14, wherein: the step of progressively introducing the carcasses into the tank comprises placing the carcasses into the tank at an inlet end; and the step of propelling the jets of heat-exchanging fluid through the body of heat-exchanging fluid in the tank comprises propelling the jets into the tank at the inlet end at a velocity that is relatively higher than the velocity of the body of heat-exchanging fluid in the tank.
 18. The method of claim 14, wherein: the step of oscillating the paddle in the tank comprises oscillating the paddle through an arc having up positions on opposite sides of the tank; and the step of propelling the jets of heat-exchanging fluid comprises propelling the jets into the tank adjacent and just above the up positions on opposite sides of the tank; such that the paddle urges the carcasses upwardly and laterally into the jets of heat-exchanging fluid, and the jets of heat-exchanging fluid urge the carcasses axially toward the outlet end of the tank.
 19. The method of claim 14, wherein: the step of progressively introducing the carcasses into the tank comprises progressively introducing the carcasses during a normal operation period, and no longer introducing the carcasses during an end of operation period; the step of oscillating the paddle comprises intermittently oscillating the paddle during the normal operation period; the step of propelling the jets comprises propelling the jets into the tank just above an upward reach of the paddle during the normal operation period; and propelling at least one jet along a bottom of the tank during the end of operation period.
 20. The method of claim 14, wherein the jets include upper jets and lower jets, the upper jets being axially propelled into the tank just above an upward reach of the paddle, and the lower jets being axially propelled along a bottom of the tank. 